1. Field of the Invention
The present invention relates to a small, high capacity disk drive apparatus with low power consumption and a method of mounting the same.
2. Description of Related Art
As is disclosed in PCT/W089/08313, now U.S. Pat. No. 4,937,785 a related art small magnetic disk drive apparatus comprises one or more magnetic disks which are about 2.5 inches in size. A rotary actuator mechanism, a magnetic head positioning servo mechanism and power saving means are also mentioned therein.
Specifically, the rotary actuator mechanism includes an arm assembly having a cam follower for dynamically loading and unloading the magnetic head.
The servo mechanism enhances the accuracy of head positioning by reducing an external force applied upon the servo actuator and includes hardware and software for saving the consumed electric power.
The other prior art which is disclosed in the Japanese Unexamined Patent Publication No. 62-256295 relates to a light weight and inexpensive disk drive apparatus in which the circuit board functions as the dust cover.
In order to mount the disk drive apparatus within an information processing system, it is necessary to connect the disk drive apparatus with a unit mounted to a printed wiring board or to connect the disk drive apparatus with a power supply. In order to reduce the number of cables in this case, there has been utilized a printed wiring board which is provided with a connector electrically connected with the disk drive apparatus, for connecting to and from the printed wiring board electrical signals inputted and outputted to and from the disk drive apparatus.
The prior art will be described with reference to FIG. 26.
A plurality of disk drive apparatuses 32 are secured to a printed wiring board 31 by screws and the like.
A connector 33 which electrically connects the printed wiring board 31 with a disk drive apparatus 32 is mounted upon the printed wiring board 31 in the vicinity of the disk drive apparatus 32. A cable 36 having a connector from the disk drive apparatus 32 is connected to the connector 33.
A connector 34 for external connection is mounted on the printed wiring board 31 at one end thereof.
The printed wiring board 31 has such an outer dimension that the board can be mounted upon a printed wiring board mounting unit 40.
A connecting printed wiring board 41 is disposed at the rear side of the printed wiring board mounting unit 40.
The connecting printed wiring board 41 is provided with circuits for a power supply and signal circuits and a connector 42 which will be connected with the connector 34 of the printed wiring board .31.
The printed wiring board mounting unit 40 is provided with guiding grooves 43 for guiding and positioning the printed wiring boards 31 so that the printed wiring boards 31 can be positively secured.
This mounts the printed wiring boards 31 to the printed wiring board mounting unit 40 simultaneously with the electrical connection with the connecting printed wiring board 41.
Accordingly, the disk drive apparatus 32 is connected with an external device via the connector 34 and a printed circuit on the printed wiring board 31. A cable which directly connects the external device with the disk drive apparatus 32 is thus not necessary.
Such a prior art is also described in Japanese Unexamined Patent Publication No. 1-12586.
However, the disk drive apparatus in the prior art has not taken into consideration such developments as miniaturization to less than 2.5 inches in size, high density recording, rotational speed of the spindle motor, control method and power supply method. There have been problems in mounting space and power consumption of the disk drive apparatus and the performance of the associated electronic circuit.
The number of cables which connect a group of disk drive apparatuses on the printed wiring board 31 with an external device has been reduced by mounting a plurality of disk drive apparatuses 32 on the same printed wiring board 31 and by connecting each disk drive apparatus 32 with the external device via the connector 34 provided on the printed wiring board 31.
Accordingly, the printed wiring board 31 is merely used for mounting mainly disk drive apparatuses 32.
There is also a problem that the group of the disk drive apparatuses 32 is connected with the printed wiring board 31 via the cable 36 with a connector of the disk drive apparatus 32 and the connector 33 on the printed wiring board 31.
In other words, the connector portion and cable connection occupies a greater area of the mounting board or the disk drive in the prior art even if the disk drive is miniaturized. The miniaturization of the disk drive has not been effective.
Mounting of the disk drive apparatus 32 and an information processing unit including a CPU and memory elements to the same board has not been considered.